Dual blade ophthalmologic surgery device

ABSTRACT

A dual blade device and method useable for performing an ab interno procedure within a human eye to remove a strip of trabecular meshwork tissue.

RELATED APPLICATIONS

This application is a division of U.S. patent application Ser. No.15/076,624 filed Mar. 21, 2016, which is a continuation of U.S. patentapplication Ser. No. 14/789,632 filed Jul. 1, 2015 and issued as U.S.Pat. No. 9,358,155 on Jun. 7, 2016, which is a continuation of U.S.patent application Ser. No. 14/481,754 filed Sep. 9, 2014 and issued asU.S. Pat. No. 9,107,729 on Aug. 18, 2015, which is a division of U.S.patent application Ser. No. 13/159,356 filed Jun. 13, 2011 and nowabandoned, which is a division of U.S. patent application Ser. No.10/560,267 filed May 11, 2006 and issued as U.S. Pat. No. 7,959,641 onJun. 14, 2011, which is a 35 U.S.C. § 371 national stage of PCTInternational Patent Application No. PCT/US2004/018488 filed Jun. 10,2004, which claims priority to U.S. Provisional Patent Application No.60/477,258 filed on Jun. 10, 2003, the entire disclosure of each suchprior patent and application being expressly incorporated herein byreference.

BACKGROUND OF THE INVENTION

There are numerous medical and surgical procedures in which it isdesirable to cut and remove a strip of tissue of controlled width fromthe body of a human or veterinary patient. For example, it may sometimesbe desirable to form an incision of a controlled width (e.g., anincision that is wider than an incision made by a typical scalpel orcutting blade) in the skin, mucous membrane, tumor, organ or othertissue or a human or animal. Also, it may sometimes desirable to removea strip or quantity of tissue from the body of a human or animal for useas a biopsy specimen, for chemical/biological analysis, for retention orarchival of DNA identification purposes, etc. Also, some surgicalprocedures require removal of a strip of tissue of a known width from ananatomical location within the body of a patient.

One surgical procedure wherein a strip of tissue of a known width isremoved from an anatomical location within the body of a patient is anophthalmological procedure used to treat glaucoma. This ophthalmologicalprocedure is sometimes referred to as a goniectomy. In a goniectomyprocedure, a device that is operative to cut or ablate a strip of tissueof approximately 2-10 mm in length and about 50-200 μm in width isinserted into the anterior chamber of the eye and used to remove a fullthickness strip of tissue from the trabecular meshwork. The trabecularmeshwork is a loosely organized, porous network of tissue that overliesa collecting canal known as Schlemm's canal. A fluid, known as aqueoushumor, is continually produced in the anterior chamber of the eye. Innormal individuals, aqueous humor flows through the trabecular meshwork,into Shlemm's Canal and out of the eye through a series of ducts. Inpatients who suffer from glaucoma, the drainage of aqueous humor fromthe eye may be impaired by elevated flow resistance through thetrabecular meshwork, thereby resulting in an increase in intraoccularpressure. The goniectomy procedure can restore normal drainage ofaqueous humor from the eye by removing a full thickness segment of thetrabecular meshwork, thus allowing the aqueous humor to drain throughthe open area from which the strip of trabecular meshwork has beenremoved. The goniectomy procedure and certain prior art instrumentsuseable to perform such procedure are described in U.S. patentapplication Ser. No. 10/052,473 published as No. 2002/011608A1(Baerveldt), the entirety of which is expressly incorporated herein byreference.

At present there remains a need in the art for the development ofsimple, inexpensive and accurate instruments useable to perform thegoniectomy procedure as well as other procedures where it is desired toremove a strip of tissue from a larger mass of tissue.

SUMMARY OF THE INVENTION

The present invention provides a device for cutting a strip of tissue ofapproximate width W from a mass of tissue. The device generallycomprises a) an elongate cutting tube that has a distal end and a lumenthat opens through an opening in the distal end and b) first and secondcutting edges formed on generally opposite edges of the distal end ofthe cutting tube and separated by a distance D. The cutting tube isadvanceable through tissue such that the first and second cutting edgeswill cut a strip of tissue having approximate width W, wherein theapproximate width W is approximately equal to the distance D between thefirst and second cutting edges. In some embodiments, the strip of tissuemay be aspirated or otherwise removed through the lumen of the cuttertube. In some embodiments, the device may include apparatus useable tosever (e.g., transversely cut or transect) the strip of tissue when thestrip of tissue has reached a desired length.

Further in accordance with the invention there is provided a method forcutting a strip of tissue of width W from a tissue mass. This methodgenerally comprises the steps of a) providing a device that comprises i)an elongate cutting tube that has a distal end and a lumen that opensthrough an opening in the distal end and ii) first and second cuttingedges formed on generally opposite edges of the distal end of thecutting tube and separated by a distance D that is approximately equalto the width W of the strip of tissue to be cut; and b) advancing thedistal end of the cutting tube through the mass of tissue such that thefirst and second cutting edges cut a strip of tissue of approximatewidth W. Further aspects and elements of the invention will beunderstood by those of skill in the art upon reading the detaileddescription of specific examples set forth herebelow.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a system incorporating a needle cuttingdevice of the present invention.

FIG. 2 is an enlarged perspective view of section 2 of FIG. 1.

FIGS. 3A-3D show various steps in a method for manufacturing a needlecutter of the present invention.

FIG. 4 is a side view of a distal portion of a needle cutter device ofthe present invention being used to cut a strip of tissue of approximatewidth W.

FIG. 5 is a perspective view of the distal portion of a needle cuterdevice of the present invention incorporating apparatus for severing astrip of tissue cut by the needle cutter device after the strip oftissue has reached a desired length.

FIG. 6 is a side view of the distal portion of another embodiment of aneedle cutter device of the present invention having a plurality ofcurves or bends formed in the cutting tube.

DETAILED DESCRIPTION

The following detailed description, and the drawings to which it refers,are provided for the purpose of describing and illustrating certainpreferred embodiments or examples of the invention only, and no attempthas been made to exhaustively describe all possible embodiments orexamples of the invention. Thus, the following detailed description andthe accompanying drawings shall not be construed to limit, in any way,the scope of the claims recited in this patent application and anypatent(s) issuing therefrom.

One example of a needle cutter device 10 of the present invention isshown in FIGS. 1-4. This needle cutter device 10 generally comprises anelongate cutting tube 14 that has a distal end and a lumen 27 that opensthrough an opening in the distal end. First and second cutting edges 20,22 are formed on generally opposite edges of the distal end of thecutting tube 14. These first and second cutting edges 20, 22 areseparated by a distance D, as shown in the distal end view of FIG. 3B.In the particular example shown in the drawings, the first and secondcutting edges 20, 22 are located on opposite lateral sides of the distalend of the cutting tube 14 and a blunt, protruding tip 24 is located onthe bottom of the distal end of the cutting tube. Also, a blunt edge 26is located at the top of the distal end of the cutting tube 14. Thus,only the lateral cutting edges 20, 22 are sharp and intended to cuttissue. The blunt, protruding tip 24 can, in some applications, beconfigured and used to facilitate insertion of the device 10 to itsintended location and/or the blunt protruding tip 24 may be placed in ananatomical or man made grove or channel (e.g., Schlemm's Canal of theeye) such that it will then advance through the channel or groove andguide the advancement and positioning of the remainder of the device 10.

One or more bends or curves may optionally be formed in the cutting tube14 to facilitate its use for its intended purpose. For example, in theembodiment of the device 10 shown in FIG. 2, a single bend 17 ofapproximately 90 is formed near the distal end of the cutting tube 14.In the embodiment of the device 10 b shown in FIG. 6, two separate bendsof approximately 90 degrees each are formed at spaced apart locations onthe cutting tube 14, thereby giving the cutting tube 14 a generally Ushaped configuration. It will be appreciated that any number of bends orcurves, in any direction and of any severity may be formed in thecutting tube 14 to facilitate its use in specific procedures or toenable it to be inserted through tortuous anatomical channels of thebody. In most cases, the degree of curvature in embodiments where asingle bend or curve is formed will be between approximately 30 andapproximately 90 degrees and in embodiments where more than one bend orcurve are formed in the cutting tube 14 each such bend or curve willtypically be between approximately 15 to approximately 90 degrees.

As shown in FIG. 4, when the cutting tube 14 is advanced through tissue,distal end first, the first and second cutting edges 20, 22 will cut astrip ST of tissue having approximate width W, such approximate width Wbeing approximately equal to the distance D between the first and secondcutting edges 20, 22. The severed strip ST of tissue will enter thelumen 27 of the cutting tube 14 as the device advances. Negativepressure may be applied to lumen 27 to aspirate the strip ST of tissueand/or fluid and/or other matter through lumen 27.

The device 10 may optionally include a second lumen. Such second lumenmay be used for infusion of fluid through the device 10 or for otherpurposes. In the embodiment shown in FIGS. 1 and 2, the device 10comprises an outer tube 16 in addition to the cutting tube 14. Thecutting tube 14 is of smaller diameter than the outer tube 16 and thecutting tube 14 may extend through the lumen 19 of the outer tube 16such that a distal portion of the cutting tube 14 extends out of andbeyond the distal end of the outer tube 16, as may be seen in FIG. 2.The distal end of the outer tube 16 is tapered and in closeapproximation with the outer surface of the cutting tube 14. Fluid maybe infused through the lumen 19 of the outer tube 16, through the spacebetween the outer surface of the cutting tube 14 and the inner surfaceof the outer tube 16. Fluid that is infused through the lumen 19 of theouter tube 16 may flow out of one or more apertures 11 formed near thedistal end of the outer tube.

In some embodiments, the device 10 may be equipped with severingapparatus for severing (e.g., transversely cutting or transecting) thestrip ST of tissue to fully excise or detach the strip ST of tissue fromthe remaining tissue mass and/or from the body of a human or animalsubject. Such severing apparatus may comprise any suitable type oftissue cutter such as a blade, scissor, guillotine, electrode(s), laser,energy emitting tissue cutter, mechanical tissue cutter, etc. FIG. 5shows an example of an embodiment of the device 10 a wherein monopolaror bipolar electrode(s) 40 are located on the distal end of the cuttingtube 14. When it is desired to sever the strip ST of tissue, theelectrode(s) is/are energized with sufficient energy to sever the stripST, thereby disconnecting the strip ST from the remaining tissue massand/or the body of the human or animal subject.

In some embodiments of the device 10, the cutting edges 20, 22 may beheated such that they will cauterize as the cut. As those of skill inthe art will appreciate, such heating of the cutting edges 20, 22 may beaccomplished by placement of electrode(s) near the cutting edges 20, 22such that, when the electrode(s) is/are energized, the cutting edges 20,22 will become heated to a temperature suitable for the desiredcauterization function.

The needle cutter device 10 of the present invention may optionally beused as part of a system 12, as shown in FIG. 1. The basic components ofthe system 12 comprise an aspiration pump module 74 and a source ofirrigation fluid 72, mounted on a surgical roller cart 70. Control ofthe console functions during procedures may be accomplished by anaspiration foot pedal 78 which controls an aspiration pump 74 andvariation in the height of the source of infusion fluid 72 to change thegravity fed pressure or flow rate of infusion fluid through the device.A pinch valve, or other means, may also be incorporated in the consoleto control flow of the irrigation fluid to the needle cutter device 10.In embodiments that include apparatus (e.g., electrode(s)) for heatingthe cutting edges 20, 22 and/or for severing the strip ST of tissue(FIG. 5), the system 11 may additionally comprise an electrical currentsource, such as an electrosurgical generator 76 and electrosurgical footpedal 80 which controls the electrosurgical generator to deliver desiredamount(s) of energy to the electrode(s) or other electrical elements(e.g., resistance heater(s), etc.) on the device 10. As an option, allof the basic control functions of system 12 may be integrated into asingle footpedal to facilitate use.

The device 10 may be provided as a pre-sterilized, single-use disposableprobe or tip that is attachable to a standard surgicalirrigation/aspiration handpiece such as that commercially available asThe Rhein I/A Tip System from Rhein Medical, Inc., Tampa, Fla. After thedevice 10 has been attached to the handpiece, it may be connected to anyor all of the electrosurgical generator module 76, aspiration pumpmodule 74 and the source of irrigation fluid 72, as shown. Thus, thedevice 10 may be fully equipped for irrigation, aspiration, andelectrosurgical capabilities, as described herein.

FIGS. 3A-3D show an example of a method for manufacturing the cuttingtube 14 from standard tubing (e.g., stainless steel hypodermic tubing).Initially, the distal end of a tube is cut to form the lateral cuttingedges 20, 22, the protruding tip 24 and the blunt top edge 26.Thereafter, if it is desired to have one or more bends or curves in thecutting tube 14, angular cut out(s) 30 may be formed in the tube 14, asshown in FIG. 3C. Thereafter, the tube 14 is bent to bring the edges ofeach angular cut out 30 into apposition and weld, adhesive or otherjoining techniques are used to weld or join the opposed edges of the cutouts together, thereby forming the desired bend(s) or curve(s) in thecutting tube 14. Likewise, if it is desired to have one or more bends orcurves in the cutting tube 14, the tube 14 may be directly bent to formsaid curves or bends without the use of angular cut outs(s) 30. It maybe appreciated that the use of angular cut-out(s) 30 allow a tube 10 ofa given diameter to incorporate a curve or angle in a more compact formthan is possible by bending tubing 10 of a given diameter to said curveor angle without kinking or damaging tube 10.

The device 10 and system 12 are useable to perform a variety ofprocedures wherein it is desired to form an incision or opening of adesired width or to remove, from a mass of tissue, a strip ST of tissueof a desired width.

One particular procedure that may be performed to treat glaucoma, usingthe device 10 and system 12 of the present invention, is a goniectomy.As explained herein a goniectomy procedure is an ab interno surgicalprocedure wherein a sector of the trabecular meshwork is removed fromthe eye of the patient to facilitate drainage of aqueous humor from theanterior chamber of the eye through Schlemm's Canal and the associatedcollector channels, thereby relieving elevated intraocular pressure.

To perform a goniectomy procedure using the device 10, first a smallincision is made in the cornea at about 3 o'clock in the left eye, or atabout 9 o'clock in the right eye. A 1.5 mm slit knife may be used tomake this incision.

The device 10 is attached to the source of irrigation fluid 72 (e.g.,basic balanced salt solution) such that irrigation fluid will flowthrough lumen 19 of the outer tube 16 and out of outflow aperture 11.The device 10 is then inserted through the incision and into theanterior chamber of the eye (with irrigation flowing). In some cases,during the insertion of the device 10, the source of irrigation fluid 72may initially connected to the device such that the irrigation fluidwill flow through the lumen 27 of the cutter tube 14. In this manner,irrigation fluid will begin to infuse into the anterior chamber of theeye as soon as the distal end of the cutter tube 14 has entered theanterior chamber, rather than being delayed until the larger outer tube16 and aperture 11 have been advanced through the incision and into theanterior chamber. By this alternative approach, irrigation fluid may becaused to flow out of the distal end of the cutter tube 14 as the device10 is being inserted, thereby spreading or opening the incision byhydraulic force while in addition increasing the fluid pressure in theanterior chamber. Such spreading or opening of the incision mayfacilitate advancement of the larger diameter outer tube 16 through theincision. Pressurizing the fluid in the anterior chamber causes theanterior chamber to deepen and may facilitate maneuvering of device 10within the anterior chamber. In cases where this alternative approach isused, the source of infusion fluid 72 may be disconnected from lumen 27of the cutter tube 14 after the device 10 has been inserted into theanterior chamber and, thereafter, the infusion fluid source 72 may bereconnected to lumen 19 of outer tube 16 such that infusion fluid willflow out of aperture 11. Negative pressure (e.g., via aspiration pumpmodule 74) may then be applied to lumen 27 of the cutter tube 14 so asto aspirate fluid and debris through lumen 27 as shown in FIG. 4. Thevertical height of the infusion fluid source 72 may be adjusted toprovide sufficient gravity feed of infusion fluid to make up for thevolume of fluid or matter being aspirated from the anterior chamberthrough lumen 27, thereby maintaining the desired pressure of fluidwithin the anterior chamber during the procedure.

A lens device (e.g., Ocular Swan-Jacob Autoclavable Gonioprism, ModelOSJAG, Ocular Instruments Inc., Bellevue, Wash.) may be positioned onthe anterior aspect of the eye to enable the physician to clearlyvisualize the angle of the eye where the segment of trabecular meshworkis to be removed. Under direct visualization, the device 10 is advanceduntil the distal tip of the cutter tube 14 is positioned adjacent to thetrabecular meshwork at the location where the strip ST is to be removed.Thereafter, the protruding tip 24 is advanced through the trabecularmeshwork and into Schlemm's Canal.

The device 10 is then advanced along Schlemm's Canal, thereby causingthe cutting edges 20, 22 to cut a strip of the trabecular meshwork,thereby creating an opening through which aqueous humor may drain fromthe anterior chamber of the eye.

After a strip of tissue of the desired length (e.g., about 2-10 mm) hasbeen cut by the lateral cutting edges 20, 22, any optional tissuesevering apparatus (e.g., electrode(s) 40 may be used (if present) totransect or sever the strip ST of tissue thereby disconnecting it fromthe patient's body and allowing it to be aspirated or drawn into orthrough lumen 27.

Thereafter, the aspiration is stopped, the device 10 is removed from theeye, and the infusion is stopped.

Following completion of the surgery, aqueous humor will drain from theanterior chamber through the opening that was created by removal of thestrip of tissue from the trabecular meshwork TM.

Although the invention has been described above with respect to certainembodiments and examples, it is to be appreciated that such embodimentsand examples are non-limiting and are not purported to define allembodiments and examples of the invention. Indeed, those of skill in theart will recognize that various modifications may be made to theabove-described embodiments and examples without departing from theintended spirit and scope of the invention and it is intended that allsuch modifications be included within the scope of the following claims.

What is claimed is:
 1. A dual blade device useable for performing an abinterno procedure within a human eye to remove a strip of trabecularmeshwork tissue, said device comprising: a handle configured to begrasped by an operator's hand; an elongate probe shaft that extends fromthe handle along a longitudinal axis to a distal end; a tip portion thatextends along a second longitudinal axis from the distal end of theprobe shaft to form an angle of approximately 30 degrees toapproximately 90 degrees relative to the longitudinal axis of the shaft,the tip portion being configured to penetrate through the trabecularmeshwork tissue and having a transverse width, a top surface, a bottomsurface and a terminal end, the transverse width of the tip portionbeing narrowest at its terminal end; first and second spaced apartcutting edges configured to simultaneously cut tissue that passes overthe top surface of the protruding tip and into contact with the firstand second spaced apart cutting edges; and a top edge that traversesabove an area between the first and second spaced apart cutting edges;wherein; a) the top surface of the tip portion extends from the terminalend of the tip portion to the first and second spaced apart cuttingedges; b) a distal portion of the probe, inclusive of the tip portion,is sized to pass through an incision formed in the eye; c) the tipportion is sized to fit within Schlemm's Canal of the human eye and,when so positioned, is advanceable through Schlemm's Canal withtrabecular meshwork tissue passing over its top surface and into contactwith the first and second spaced apart cutting edges; d) the first andsecond spaced apart cutting edges are formed on generally opposite edgesof the distal end of the elongate probe shaft and are separated by adistance D; and e) the first and second spaced apart cutting edges facetowards the second longitudinal axis of the tip portion.
 2. A deviceaccording to claim 1 wherein the first and second spaced apart cuttingedges cut a strip of trabecular meshwork tissue having a width W that issubstantially equal to the distance D.
 3. A device according to claim 1useable for cutting a sector of trabecular meshwork tissue having alength of 2 to 10 millimeters.
 4. A device according to claim 1 whereinthe bottom surface of the blunt protruding tip extends at an angle ofapproximately 90 degrees relative to the adjacent longitudinal axis ofthe shaft.
 5. A system comprising a device according to claim 1 incombination with a 1.5 mm slit knife for forming said incision in thehuman eye.
 6. A device according to claim 1 wherein the device ismanually operable to remove a strip of trabecular meshwork tissue.
 7. Adevice according claim 1 wherein the shaft comprises a tube having atleast one lumen.
 8. A method for using a device according to claim 1,said method comprising the steps of: forming an incision in an eye of apatient; inserting the device through the incision and into an anteriorchamber of the eye; advancing the device across the anterior chamberuntil the tip portion is positioned within the anterior chamber adjacentto trabecular meshwork tissue; causing the tip portion to penetratethrough the trabecular meshwork and to become positioned within aSchlemm's canal of the eye such that the trabecular meshwork tissue isin contact with the top surface of the tip portion; moving the device tocause the tip portion to advance through the Schlemm's Canal such thatthe trabecular meshwork tissue moves along the top surface of the tipportion and into contact with the first and second spaced apart cuttingedges, thereby cutting a strip of the trabecular meshwork tissue.
 9. Amethod according to claim 8 further comprising the step of keeping theanterior chamber filled.
 10. A method according to claim 9 wherein thedevice further comprises an infusion lumen and wherein fluid is infusedthrough the infusion lumen to keep the anterior chamber filled.
 11. Amethod according to claim 8 wherein the eye is a left eye and theincision is formed at approximately a 3 o'clock position of the eye. 12.A method according to claim 8 wherein the eye is a right eye and theincision is formed at approximately a 9 o'clock position on the eye. 13.A method according to claim 8 wherein the incision is a cornealincision.
 14. A method according to claim 8 wherein the strip oftrabecular meshwork tissue that is cut has a length of about 2 to 10millimeters.
 15. A method according to claim 8 further comprisingpressurizing the anterior chamber to cause the anterior chamber todeepen.
 16. A method according to claim 15 wherein the step ofpressurizing the anterior chamber comprises introducing a fluid into theanterior chamber.
 17. A method according to claim 16 wherein the devicefurther comprises an infusion lumen and wherein the fluid is introducedthrough the infusion lumen and into the anterior chamber.
 18. A methodaccording to claim 8 further comprising placing a lens on the eye andusing the lens to directly visualize the step of advancing the deviceacross the anterior chamber until the tip portion is positioned withinthe anterior chamber adjacent to trabecular meshwork tissue.